Patent application title: Hand truck

Abstract:

A hand truck includes a frame, a telescopic handle pivotally connected
with the frame, and a joint structure assembled between the frame and the
handle. The frame is disposed with a collapsible wheel unit adjustable in
position, and the handle and the frame can be bent and extended to a
proper length and then fixed in position so that a user can push the hand
truck with convenience. Further, the hand truck can be shaped alternately
into a two-wheel vertical truck or a four-wheel platform hand truck.

Claims:

1. A hand truck comprising:a frame having two opposite frame rods
respectively assembled with a collapsible wheel unit, said two frame rods
respectively having the outer end formed with a fitting portion;a handle
pivotally connected with said frame rods of said frame, said handle
having the opposite lower ends respectively provided with a positioning
slide slot, an elastic member, a slide-engage member, a lateral
positioning rod and a lateral pull rod, said two elastic members
respectively fitted in the opposite tube holes of said handle, each
elastic member having one end resisting against said lateral positioning
rod, said two slide-engage members respectively inserted in the inner
diameters of said handle, each elastic member having the other end
pushing against one end of said slide-engage member, said two
slide-engage members pressed to have their insert holes respectively
aligned to the opposite ends of said lateral pull rod, said lateral pull
rod firmly engaged in said insert holes of said slide-engage members by
means of positioning members;a joint structure unit fitted between said
frame rods and said handle, said joint structure unit provided with two
pivotal blocks and two pivotal bases, each pivotal block and each said
pivotal base respectively having one end fixed with a fitting member,
said pivotal base and said pivotal block able to be bent after they are
combined together, said fitting member of said pivotal block and said
pivotal base respectively fitted with said fitting portion of said frame
rods and said handle, each said pivotal block having its circumferential
surface bores with a plurality of positioning holes spaced apart at
different angles; andsaid hand truck able to be adjusted and changed in
form in accordance with a user's needs.

2. A hand truck comprising:a frame composed of two wheel units and two
lengthwise frame rods, said frame rods respectively disposed with a joint
structure, said joint structure composed of two pivotal blocks and two
pivotal bases; anda handle pivotally combined with said joint structure
of said frame rods, said handle having its upper ends fitted with a
telescopic hand grip, said handle provided with a lateral positioning rod
and a lateral pull rod, said telescopic grip able to be retracted in or
extended out of said handle and fixed in position.

Description:

BACKGROUND OF THE INVENTION

[0001]1. Field of the Invention

[0002]This invention relates to a hand truck, particularly to one having
multi-function and able to be converted into a two-wheel hand truck or a
four-wheel hand truck, able to be collapsed and convenient in use.

[0003]2. Description of the Prior Art

[0004]Hand trucks frequently used at present include two-wheel hand trucks
and four-wheel hand trucks to be optionally chosen for use, but these two
kinds of conventional hand trucks can be used for carrying and
transporting goods only under a single form. Substantially, different
kinds of goods have to be carried and transported by different kinds of
hand trucks. For instance, some goods can be carried and transported
comparatively conveniently and quickly, while others can be carried and
transported by a conventional platform hand truck comparatively steadily.
However, the conventional vertical or platform hand trucks is used to
carry goods only in a single form, but cannot be changed in forms;
therefore, if a user has to use the two conventional hand trucks
alternately, he has to purchase two different kinds of hand trucks, thus
increasing expense and taking too much space. A hand truck disclosed in a
U.S. Pat. No. 6,938,905, which is designed by the inventor of this
invention, can solve such a problem; nevertheless, this hand truck has
something necessary to be improved, inclusive of disassembling and
collapsing of its handle and wheels.

SUMMARY OF THE INVENTION

[0005]The objective of this invention is to offer a hand truck able to be
collapsed and shaped alternately into a two-wheel or a four-wheel hand
truck according to a user's needs, convenient in use.

BRIEF DESCRIPTION OF DRAWINGS

[0006]This invention will be better understood by referring to the
accompanying drawings, wherein:

[0007]FIG. 1 is an exploded perspective view of a hand truck in the
present invention;

[0008]FIG. 2 is a perspective view of the hand truck in the present
invention;

[0009]FIG. 3 is a perspective view of the hand truck in a using condition
in the present invention;

[0010]FIG. 4 is a perspective view of the hand truck in another using
condition in the present invention;

[0011]FIG. 5 is a cross-sectional view of a wheel unit fixed in position
in the present invention;

[0012]FIG. 6 is another cross-sectional view of the wheel unit fixed in
position in the present invention;

[0013]FIG. 7 is a perspective view of a handle in a stretched condition in
the present invention; and

[0014]FIG. 8 is a perspective view of the hand truck in a collapsed
condition in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015]A preferred embodiment of a hand truck in the present invention, as
shown in FIGS. 1 to 8, includes a frame 1, a handle 2, a joint structure
3 and positioning members (N) as components combined together.

[0016]The frame 1 has its opposite frame rods 10 respectively assembled
thereon with a wheel unit 11 able to be collapsed and respectively
provided with a fitting member 12 and positioning holes 13. Each wheel
unit 11 is composed of a wheelbase 110, a wheel 111 and an
angle-adjusting device 112, which consists of a pull member 1120, a
positioning member 1121, a positioning plate 1122, an elastic member 1123
and a cover 1124. The positioning member 1121, the positioning plate 1122
and the pull member 1120 are pressed by the elastic member 1123, letting
the positioning member 1121 inserted in the positioning hole 13 of the
frame rod 10, and the positioning plate 1122 and the positioning member
1121 are controlled by the pull member 1120. When the pull member 1120 is
pulled upward, the positioning plate 1122 and the positioning member 1121
will be actuated to move up, and the positioning member 1121 will be
moved away from the positioning hole 13 of the frame rod 10. At this
time, the wheel unit 11 can be collapsed or stretched out easily.

[0017]The handle 2 assembled with the frame rods 10 of the frame 1 has its
lower sides provided with two positioning slide slots 20 opposite to each
other, two elastic members 21, two slide-engage members 22, a lateral
positioning rod 23 and a lateral pull rod 24. The two elastic members 21
are respectively fitted in the tube holes of the handle 2, having one end
resisting against the lateral positioning rod 23. The two slide engage
members 22 are respectively inserted in the inner diameters of the handle
2, letting the outer end of the elastic member 21 push against one end of
the slide-engage member 22. Afterward, the slide-engage members 22 are
pressed to have their insert holes 220 respectively aligned to the two
positioning slide slots 20, and then the lateral pull rod 24 has its
opposite ends respectively inserted in both the position-slide slot 20
and the insert hole 220 and firmly positioned therein by a positioning
member (N), letting the slide-engage members 22 controlled by the lateral
pull rod 24 to slide in the inner diameters of the handle 2. Further, the
two slide-engage members 22 have their lower ends respectively secured
with a positioning stud 221, and the handle 2 has its upper end provided
with a control member 25 and fitted therein with a telescopic U-shaped
grip 26 bored with a plurality of positioning holes 260, with the control
member 25 adjusting the telescopic grip 26 in height and fixing it in
position. The handle 2 further has its opposite lower ends respectively
formed with a fitting portion 27.

[0018]The joint structure 3 fitted between the frame rods 10 and the
handle 2 is provided with two pivotal blocks 30 and two pivotal bases 31.
After pivotally combined together, the pivotal block 30 and the pivotal
base 31 can be bent if necessary. The two pivotal blocks 30 respectively
have one end fixed with a fitting member 32 to be fitted with the fitting
member 12 of the two frame rods 10, and the two pivotal bases 31
respectively have one end fixed with a fitting member 33 to be fitted
with the fitting portion 27 of the handle 2. Further, each pivotal block
30 has its circumferential surface bored with positioning holes 300, 301
and 302 at different angles for the positioning stud 221 of the
slide-engage member 22 of the handle 2 to be inserted and positioned
therein, thus enabling the handle 2 to be firmly positioned at different
angles. The two wheel units 11 are respectively secured on the opposite
frame rods 10 by means of positioning members (N).

[0019]In using, to shape the hand truck into a two-wheel hand truck,
firstly, pull out a cargo fender from the frame 1 and position it at an
angle of 90 degrees and then pull the pull members 1120 of the
angle-adjusting devices 112 of the wheel unit 11 under the frame 1 to let
the positioning members 1121 moved away from the positioning holes 13 of
the frame rods 10. Next, collapse inward the wheels 111 and release the
pull member 1120 and at this time, the positioning member 1121 will be
pressed by the elastic member 1123 to be inserted into the positioning
hole 13 at another angle, thus finishing assembly of a two wheel hand
truck, as shown in FIG. 3.

[0020]To shape the hand truck into a four-wheel hand truck, simply pull
the pull members 1120 of the angle-adjusting devices 112 to let the
positioning members 1121 moved away from the positioning holes 13 of the
frame rods 10, and after stretching out the wheels 111 and fixing them in
position, release the pull member 1120. At this time, the positioning
members 1121 will be pressed by the elastic member 1123 to be inserted
into the positioning hole 13 at another angle. Next, pull upward the pull
rod 24 of the handle 2 to actuate the positioning studs 221 of the
slide-engage members 22 to move away from the positioning holes 302 of
the pivotal blocks 30 and, after bending the handle 2 upward for 90
degrees and positioning it perpendicular to the frame 1, release the pull
rod 24. At this time, the slide-engage members 22 will be pressed
downward by the elastic members 21 to have their positioning studs 221
respectively fitted in the positioning holes 301 of the pivotal blocks 30
to finish assembly of a four wheel hand truck, as shown in FIG. 4.

[0021]To collapse the hand truck, firstly, the wheel units 11 are
collapsed inward to be positioned under the frame 1 by means of the
angle-adjusting devices 112 and then the pull rod 24 of the handle 2 is
pulled upward to force the positioning studs 221 of the slide-engage
members 22 to move away from the positioning holes 301 of the pivotal
block 30. Next, the handle 2 is collapsed inward to be laid on the frame
1 and at this time, the slide-engage members 22 will be pressed down by
the elastic members 21 to have their front positioning studs 221
respectively engaged in the positioning holes 300 of the pivotal blocks
30, as shown in FIG. 8. Thus, the hand truck is collapsed not to take
much space, and the frame 1 and the handle 2 can be stably positioned on
the frame 1 by means of the joint structure 3, convenient in operation.

[0022]As can be understood from the above description, this invention has
the following advantages.

[0023]1. After the hand truck is collapsed, the handle 2 can be stably
positioned on the frame 1 by mutual engagement of the positioning studs
221 of the slide-engage members 22 and the positioning holes 300 of the
joint structure 3.

[0024]2. The frame 1 and the handle 2 controlled by the joint structure 3
can be stably and conveniently adjusted in position as well as in angle.

[0025]3. The hand truck of this invention can be shaped alternately into a
two-wheel vertical hand truck or a four-wheel platform hand truck for use
according to a user's practical needs.

[0026]4. Both the wheels 111 and the handle 2 of the hand truck of this
invention can be collapsed, facilitating transport and saving space.

[0027]5. The telescopic U-shaped grip 26 of the handle 2 can be adjusted
in height according to a user's needs, conforming to ergonomics.

[0028]While the preferred embodiment of the invention has been described
above, it will be recognized and understood that various modifications
may be made therein and the appended claims are intended to cover all
such modifications that may fall within the spirit and scope of the
invention.